Dynamic changes of atrial septal defect area: new insights by three-dimensional volume-rendered echocardiography with high temporal resolution.

AIMS The purpose of this study was: (i) to record dynamic changes in the area of atrial septal defects (ASD) during a cardiac cycle, and (ii) to investigate factors which influence ASD dynamics. Implementation of new software modifications allowed the frame rate to be doubled, as compared to usual techniques. METHODS AND RESULTS Twenty patients were examined using transoesophageal three-dimensional (3D) echocardiography. In 10 patients the 3D dataset was recorded with a frame rate of 25Hz, in another 10 patients with a frame rate of 50Hz. The ASD area was planimetried for each picture and the changes analysed over time. The ASD area showed dynamic changes during the cardiac cycle with an end-systolic maximum and end-diastolic minimum. The influence of the various phases of the cardiac cycle on area changes could be differentiated especially at higher temporal resolution. The relative change in ASD area showed no significant relationship to Q(p)/Q(s)ratio, mean ASD size or heart rate. By contrast, there was a slight inverse correlation to age (r=-0.t45,P <0.05). CONCLUSION Transoesophageal 3D volume-rendered echocardiography permits quantitative recording of ASD dynamics. The ASD area changes are influenced especially by the various phases of the cardiac cycle.